Why does my retinol stop working over time?

Retinol degrades in the presence of water, light and oxygen.

Evidence

Source:: Temova Rakuša Ž et al. Pharmaceutics. 2021;13(10):1738
Applies to:: Formulations containing retinol
What this does not establish:: How a given product performs on your skin. Finished-product pH and concentration are rarely published, so this describes the chemistry, not a measurement of any specific product.
Last reviewed:: 2026-09-26

In practice

Retinol is unstable in the presence of water, light and oxygen. In an anhydrous (oil or silicone) base, and alongside antioxidants such as tocopherol or BHT, it keeps its potency far longer. This formula lists water high up and no obvious antioxidant support, so how much active retinol survives will depend heavily on packaging and how long the product has been open.

Dermasift analyses skincare formulations against published cosmetic science. This is information, not medical advice — for a diagnosed skin condition, speak to a dermatologist.

Check this against a product’s ingredient list

Why does my retinol stop working over time?

Retinol degrades in the presence of water, light and oxygen.

Evidence

Source:: Temova Rakuša Ž et al. Pharmaceutics. 2021;13(10):1738
Applies to:: Formulations containing retinol
What this does not establish:: How a given product performs on your skin. Finished-product pH and concentration are rarely published, so this describes the chemistry, not a measurement of any specific product.
Last reviewed:: 2026-09-26

In practice

Dermasift analyses skincare formulations against published cosmetic science. This is information, not medical advice — for a diagnosed skin condition, speak to a dermatologist.

Check this against a product’s ingredient list